In Chapter 25 we find the account of Abraham’s marriage to Keturah, following the death of Sarah. Keturah bore Abraham six more sons. This made the promise of God first given in Genesis 12, that he would become the father of many nations, even more definite. This chapter also records Abraham’s death. Whenever a great man, who has begun a great movement dies, there is concern for who will carry on. But this is not a movement begun by a man. It is God’s movement, and God will see to it that the work that He has begun will be completed (Phil. 1:6). Nothing can thwart His purpose. This section of Genesis shows that God keeps His promises.
The major part of the chapter deals with the genealogies of his senior sons, Ishmael (25: 12-18) and Isaac (25:19-34). But the focus now shifts very definitely to Isaac - the son of promise. This does not mean that the life of Isaac will be smooth and without challenges. Quite on the contrary…
The big idea and purpose of this chapter, and indeed of the whole Bible is the establishment of the chosen seed - particularly as seen in 25:23.  The apostle Paul cites this text in Romans 9:11-13 and he calls it there “God’s purpose of election”. So we need to think carefully about this important doctrine and how it applies to us. Let us do this with the help of our text. I want to anchor our theme (the doctrine of divine election) and our text in these few thoughts :
1. God’s Purpose According To His Choice Will Stand
2. God’s Choice Usually Is Contrary To Man’s Wisdom.
3. God’s Choice Proceeds From The Principle Of Grace, Not Merit.
1. God’s Purpose According To His Choice Will Stand.
God had promised to make Abraham the father of a multitude of nations (Ch. 12; 17:4). This is how it happens. Abraham’s sons by Keturah will, in time, produce a number of nations. Then our text lists the generations of Ishmael (25:12-18). Why? To make the same point- that God’s purpose according to His sovereign choice will stand. Abraham had previously asked the LORD that Ishmael might live before Him, in the sense that he should become the son of the covenant (17:18). God had denied that request because He had chosen Isaac, born of his covenant wife, Sarah. This does not mean that God would not bless Ishmael in other ways. He promised Abraham that Ishmael would become the father of twelve princes and that He would make him into a great nation (17:20). But God had also said that the sons of Ishmael would live in defiance against all his kinsmen (16:12). We see the fulfilment of this here in 25:18. Again we see that God’s purpose is accomplished according to His sovereign choice.
The blessings of the covenant however go to none of these.Our text shows that Abraham gave all that he had to Isaac (25:5). While he gave some gifts to Keturah’s sons, he sent them away (25:6). The same was true for Ishmael. He was sent away (21:8-21). Only Isaac was given the covenantal promises of blessing and the land. Thus we read that God blessed him after Abraham’s death (25:11).
The story of God’s election becomes even more fascinating as we now read concerning the birth of the twin sons of Esau and Jacob, the sons of Isaac. I want to remind you that if God was going to continue his covenantal promises to Abraham through Isaac, then Isaac needed to have children. But Rebekah the wife of Isaac, like her mother-in-law, Sarah, was barren. Isaac was 40 when he married Rebekah (25:20) and only 20 years later, when he was 60, did she give birth to the twins (25:26). While Ishmael flourished and produced 12 sons, Isaac learned the patience of barrenness. He had to learn to depend on God. Struggle produces prayer, “It is time for you to work oh Lord!” God does all things in His time. Isaac learned that the delays of God are not denials. 
Rebekah falls pregnant. Here is the fascinating part. A disturbing problem develops in her pregnancy. "The children struggled (lit. crushed, jostled) together within her, and she said, ‘If it is thus, why is this happening to me?’ (25:22). The LORD reveals to her in 25:23 that there are 2 nations within her womb. The LORD tells her that these two nations shall not be at peace with one another. Again we see that God made a choice. He tells Rebekah that two nations would come from her womb. He told her that the older (Esau) would serve the younger (Jacob). This was an inversion of the traditional norm. Usually the older would inherit the father’s blessing and the land. But it was not to be so in this case. Esau would become the father of the nation called the Edomites. Jacob, whose name was later changed to Israel (Gen 32:28) would become the father of the Israelites – God’s chosen people. In the history of the OT we discover that these two nations will be sworn enemies, even though they have the same parents, and again God’s Word is true.
So, everything in our text makes the same point. God chooses certain people to enter into a covenant- for His own purpose. This is the difficult doctrine of election. It is difficult, because we have no control over this process. It belongs to God alone. As indicated earlier, Paul picks up on this text in Genesis 25: 23 in Romans 9:11-13 and comments: “10 And not only so, but also when Rebekah had conceived children by one man, our forefather Isaac, 11 though they were not yet born and had done nothing either good or bad—in order that God's purpose of election might continue, not because of works but because of him who calls— 12 she was told, “The older will serve the younger.” 13 As it is written, “Jacob I loved, but Esau I hated.”
C. H. Spurgeon comments, “Jacob was God’s chosen one; he had set his love upon him, and before he was born, he had distinguished him as his elect one. Now this is a great deep, and there are many who argue at and question it; I am not here to answer them. The Book says so; let them argue with the Book, not with me.“
The doctrine of election runs right through the Scriptures. A.W. Pink comments:
In Genesis we see the difference which the Lord made between Nahor and Abraham, Ishmael and Isaac, Jacob hating Esau are cases to the point.
In Exodus we behold the distinction made by God between the Egyptians and the Hebrews.
In Leviticus the atonement and all the sacrifices were for the people of God.
In Numbers God used a pagan named Balaam to announce the fact that Israel were “the people” who “shall dwell alone, and shall not be numbered among the nations” (23:9);
In Deuteronomy it is recorded, “The Lord’s portion is his people; Jacob is the lot of his inheritance” (32:9).
In Joshua we behold the mercy of the Lord bestowed upon Rahab the harlot, while the whole of her city was doomed to destruction.
In Judges the sovereignty of God appears in the unlikely instruments selected, by which He brought victory for Israel: Deborah, Gideon, Samson.
In Ruth we have Orpah kissing her mother-in-law and returning to her gods, and yet Ruth cleaves to her and obtained inheritance in Israel—who made them to differ?
In 1 Samuel David is chosen for the throne, preferred to his older brothers .
In 2 Samuel we learn of the everlasting covenant with David (23:5).
In 1 Kings Elijah becomes a blessing to a single widow selected from many;
In 2 Kings Naaman alone, of all the lepers, was cleansed.
In 1 Chronicles it is written “ O offspring of Jacob, His chosen ones” (16:13); while in 2 Chronicles we are made to marvel at the grace of God bestowing repentance upon a wicked ruler , Manasseh. And so we might go on. The Psalms, Prophets, Gospels and the epistles are so full of this doctrine…
2. God’s Choice Usually Is Contrary To Man’s Wisdom
Our text shows us that God chooses contrary to human inclination. In God’s sovereignty, the Isaac’s wife was barren. His half-brother, Ishmael had not problems in fathering 12 sons. Isaac only managed to have a pair of twins, and that after 20 years of marriage, in which he pleaded with God. Again, human convention would dictate that the oldest would be chosen to be the successor. But God chose not the manly hunter Esau but, Jacob, the mommy’s boy and the deceiver. God’s choice is contrary to man’s. Paul explains in 1 Cor. 1:26-30: “26 For consider your calling, brothers: not many of you were wise according to worldly standards, not many were powerful, not many were of noble birth. 27 But God chose what is foolish in the world to shame the wise; God chose what is weak in the world to shame the strong; 28 God chose what is low and despised in the world, even things that are not, to bring to nothing things that are, 29 so that no human being might boast in the presence of God.” The logic is fairly simple. If God chose those who were strong in themselves, they would have reason to boast in themselves and God would be robbed of His glory. If God chose those who first chose Him, they could brag about their intelligent choice. But God chooses those whom the world would never choose, those who cannot choose Him. When His purpose is fulfilled through them, He gets the glory.
3. God’s Choice Proceeds On The Principle Of Grace, Not Merit.
One of the most difficult truths to grasp in the Bible is that God doesn’t operate on the merit system. He doesn’t choose those who have earned it or who show the most potential. He doesn’t choose on the basis of birth order or strength. If He did, He would have chosen Ishmael over Isaac and Esau over Jacob. And, contrary to popular opinion, God doesn’t choose those whom He knows in advance will choose Him. Many people believe that God, in His foreknowledge, looks down through the halls of history, sees who will decide for Him, and then chooses them on that basis. However, that makes God dependent on the choices of man. This is not so and that is what Paul asserts in Romans 9:11. God determined that Esau would serve Jacob, before they did anything good or bad, so that God’s purpose in election would stand. God didn’t work out His eternal plan after previewing how things would turn out. God, ahead of time sovereignly chose those whom He chose according to grace, by means of His unmerited favour. This thought often bothers people, because it supposedly takes away man’s ‘free will’ , and strips us of all choice and glory. But the truth is that no one would ever choose God if it were not for grace. Listen again to Spurgeon,
I believe the doctrine of election, because I am quite certain that, if God had not chosen me, I should never have chosen Him; and I am sure He chose me before I was born, or else He never would have chosen me afterwards; and He must have elected me for reasons unknown to me, for I never could find in myself why He should have looked upon me with special love. So I am forced to accept that great Biblical doctrine.
The idea of this being ‘unfair‘ is anticipated and discussed by Paul in Romans 9: 1-26. He asks, “Is there injustice on God’s part?” He strongly answers, “By no means!” (lit. May it never be!) Then he shows how God has mercy on whom He wills and hardens whom He wills. Then he anticipates the next objection: “You will say to me then, ‘Why does He still find fault? For who resists His will?’” Listen to the response: “But who are you O man, who answers back to God?” (Rom. 9:14-20).
The proper response is simply to submit to God and seek to obey what His Word clearly reveals, namely, that God’s sovereign purpose according to His unconditional choice will stand and that, at the same time, I am responsible to submit and obey.
Is that so difficult to understand?
When we submit and commit ourselves to God’s purpose, He surely blesses us. We go forward, and often with difficulty, but we go forward. Abraham is the prime example in our text. He submitted and committed himself to God’s purpose, and God blessed him abundantly. We read that he died “full of years” (25:8). So too with Isaac. God blessed Isaac (25:11)
The doctrine of election ought to be a doctrine of blessing, assurance and joy to every true believer.
 cf. also Malachi 1:2,3
 Donald Grey Barnhouse: Genesis Vol 2 , p.39
 Spurgeon’s Autobiography, 51.